Multiple glazed unit for test chambers



April 17, 1955 o. D. ENGLEHART ET AL ,74

MULTIPLE GLAZED UNIT FOR TEST CHAMBERS Filed March 28, 1952 Fial 11 I k 23 P zix 45W 24 14k 15 F162 r e 14 I INVENTOR Z2 Oscar D. Engleharc 28 na William S.Bobel BY Mai} ATTORNEY United States Patent LIULTIPLE GLAZED UNIT FOR TEST CHAL'IBERS Oscar .D. 'Engle'hart, Brac'kenridge, and William S. Bobel, New Kens'ington, Pa., 'assignors to Pittsburgh Plate Glass-Company Application .March 28, 1952,:Serial No.,279,-142

4 Claims. c1. 20 56.5)

This invention .relates :to whidow constructions and more particularly to :azmultiple glazedsunit Zfor .usein'test chambers wherein such ".units may :be subjected to wide seal when subjected to extreme temperature differences and to pressure differences of more than-one atmosphere in either direction.

Another object of this invention is .the provision of a multiple glazed unit which may be easily assembled in various sizes and thicknesses from .a. minimum number of stock elements.

A still further object of this invention is the provision of a multiple glazed unit having a plurality of insulating air films formed by a plurality of panes of plate or tempered glass.

Other objects and advantages of the invention will become more apparent from the following detailed description of a preferred embodiment thereof.

In the drawing,

Figure 1 is an elevational view of a multiple glazed unit installed in the Wall of a test chamber, and

Figure 2 is an enlarged fragmentary horizontal sectional view taken along line IIII of Figure 1.

Referring to the drawings, a multiple glazed unit is shown abutting a poltion of a test chamber wall 11. The unit 10 comprises an outer glass panel 12, intermediate glass panels 13, 14, 15, and 16, an inner glass panel 17, and framing elements 18, 19, and securing the glass panels together as an assembled unit. The glass panels are spaced one from another by means of spacer elements 21 positoined between the marginal portions of adjacent panels. A mastic caulking or sealing compound 22 completely fills the space between the peripheral edges of the glass panels and the framing elements 18, 19, and 20.

The glass panels 12 and 17 are preferably one-half or three-quarter inch plate glass, although tempered glass may be used in place of plate glass. The intermediate glass panels 13, 14, 15, and 16 may be one-quarter inch annealed or tempered glass. Four intermediate panels are shown, but it is to be understood that only one or more intermediate panels may be used depending on the heat insulation required in a particular installation. The heat insulation is greater when more intermediate panels are used to provide more separated air films, but visibility through the multiple glazed unit diminishes as more intermediate panels are added.

The framing elements comprise metal angle or L-shaped members 18 and 20, and a flat metal strip 19. The angle members 18 and 20 are preferably pre-rolled stainless sheet steel, and may be cut from the same strip or length. The flat strip 19 may also be of rolled stainless steel, and may be stocked in several widths to permit the assembly of units of difierent thickness and number of intermediate ice panels forsatisf-Y g the requirements :of any particular test chamber :installation. The spacer elements 21 may :be formed asa-metalitubing of metals "such as aluminum, :stainless or carbon steels. The spacers 21 are preferably .of rectangular crosssection and "may or may not contain -a desiccatingagent 29 .such as :activated alumina, .anhydrous calcium sulfate, or the like. If a desiccant is so placed, the tubing 21 shouldhave openings 30 therein to permit the desiccant to absorb moisture from the airentrapped between the glass v anels.

The multiple glazed unit .shown may be assembled as follows. .Elements 18 and 20 are cut to length from a stock section, the cuts 23-being at .-forty-five degrees 'to the length of the element. Four lengths are held together as a rectangle and the adjoining ends secured together by welding or brazing together the cut ends .23. Two such frames of identical size are prepared. Oneframe :may then havethe flat strip 1-9-secured to-the edge flange thereof by welding or brazing at 24. Sealing compound 2-2 isspread in the frame and on the peripheral edges of .theglass panels, and then panel 12-is fitted into the frame. The spacer channel or tube 21 is then sealed to the marginal portion of panel .12 with sealing compound, and panels 13, 14, 15, and. 16 alternating with additional spacers -21sealed thereto are added to build-up thedesired thickness M1111. Inner panel -17 is fitted against a spacer .2-1 and then angle strip .20 having sealing compound .22 'therein is applied against the outer surface of .panel.:1-7 and the edge'of'the strip is welded or brazed Ito the outer surface of strip 1? at 25. The assembled unit 10 has all the spaces between the edges of the glass panels and the frame strips 18, 19, and 20 filled with sealing compound 22. Additional sealing compound 26 may be applied to the end of the flange 27 of test chamber wall 11, against which panel 12 abuts, The unit 10 may be secured to the wall 11 by conventional clamps or supports forming no part of this invention. The application of pressure within the test chamber applies a force in the direction of arrow 28 to seal the unit 10 against the wall flange 27.

The sealing compound 22 may be a dispersion of carbon black in polyisobutylene of the character disclosed in Patent 2,551,952, issued May 8, 1951, in the name of Gerald E. Kunkle, but it is to be understood that any suit able mastic composition may be employed.

In mounting the assembled unit 10 in a test chamber wall it is desirable that no compression or stress be applied to the elements 18, 19, and 20 in order to prevent shifting of the glass panels 12-17 inclusive and to prevent fiow of the sealing composition 22. The unit can be mounted against a wall flange 27, as illustrated in the drawings, and it will be obvious to those skilled in the art that there are other equivalent wall chamber constructions which avoid the imposition of stresses on the unit elements 18, 19, and 20.

The multiple glazed unit construction described provides an effective vapor seal in test chamber windows even when subjected to extreme temperature differences of l00 F. to +250 F. on one side while exposed to room temperatures on the other side. The window unit construction described also withstands substantial differences in pressure from one side to the other. The vapor seal provided by the described construction is satisfactory even when the unit is exposed intermittently to humidities approaching percent.

The construction of the multiple glazed unit also makes it possible to assemble units of various sizes and thickness by keeping in stock only one rolled section 18, and sheet metal strips 19 of various widths.

It will be apparent to those skilled in the art that various modifications and variations in the nature and arrangement of the several elements of our construction are possible without departing from the spirit of this invention or the scope of the appended claims.

What we claim is:

l. A multiple glazed unit construction for use as a test chamber, window, said construction comprising a plu rality of glass panels arranged in parallel relation, a spacer element for and between the marginal portions of each adjacent pair of said glass panels, a pair of L-shaped sheet metal framing elements having edges contacting the marginal portions of the outer surface of the outer panels of said unit, and having otheredges spaced from said metal strip.

2. A multiple glazed unit construction for use as a test chamber window, said construction comprising a pair of outer glass panels and an intermediate glass panel therebetween, said panels being arranged in parallel relation, a spacer element between a marginal portion of one of said outer panels and a marginal portion of said intermediate panel, and a second spacer element between a marginal portion of the other of. said outer panels and a marginal portion of said intermediate panel, a pair of sheet metal framing elements having edges contacting the outer surface of said outer glass panels and other edges spaced from the peripheral edges of said panels, sheet metal means overlapping said other edges and positioned between said other edges and said glass panels, said sheet metal means continuously connecting one of said framing elements to the other along the periphery of said unit,

and a sealing compound filling the space between the peripheral edges of said panels and said connected framing elements.

3. A multiple glazed unit construction for use as a test chamber window, said construction comprising a pair of outer glass panels, four intermediate glass panels therebetween, said panels being arranged'in parallel relation, spacer elements between the marginal portions of adjacent panels, angular sheet metal framing elements extending around and spaced from the peripheral edges of saidglass panels and having edges engaging the outer surface of said outer panels, a flat sheet metal, connecting strip posi' tioned within andoverlapping and secured to said framing elements extending around and spaced from the peripheral edges of said glass panels, and a mastic sealing compound filling the space between said framing elements, connect ing strip and the peripheral edges of said glass panels.

4. A multiple glazed unit construction as defined in claim 3 and in which said outer glass panels are of substantially greater thickness than the thickness of said intermediate glass panels.

References Cited in the file of this patent UNITED STATES PATENTS 2,129,072 Rutishauser -i- Sept. 6, 1938 2,189,388 Zand Feb. 6, 1940 2,525,717 Ottenheimer Oct. 10, 1950 V FOREIGN PATENTS 527,822 Great Britain Oct. 16, 1940 

